A power block (1) with an electrified track (2), of the type of power blocks for lighting systems constructed in an extruded metal profile wherein the track (2) is made in insulating material and in a "U" shape with open wings (2.1) with respective projections (2.2) facing opposing their respective wings (2.1), arranged at mid height and in the form of an irregular arch with the free end (2.3) radially sectioned.